Image-guided brachytherapy for cervical cancer: Analysis of D2 cc hot spot in three-dimensional and anatomic factors affecting D2 cc hot spot inorgans at risk

Academic Article

Abstract

  • Purpose: To analyze the D hot spot in three-dimensional CT and anatomic factors affecting the D hot spot in organs at risk (OARs). Methods and Materials: Thirty-one patients underwent pelvic CT scan after insertion of the applicator. High-dose-rate treatment planning was performed with standard loading patterns. The D structures in OARs were generated in three dimensional if the total equivalent dose in 2Gy exceeded our defined dose limits (hot spot). The location of D hot spot was defined as the center of the largest D fragment. The relationship between the hot spot and the applicator position was reported in Digital Imaging and Communication in Medicine coordinates. Results: The location of sigmoid, small bowel, and bladder D hot spots was around the endocervix: The mean location of sigmoid hot spot for lateral view was 1.6cm posteriorly and 2.3cm superiorly (Y, 1.6 and Z, 2.3), small bowel was 1.6cm anteriorly and 2.7cm superiorly (Y, -1.6 and Z, 2.7). The mean location of bladder hot spot was 1.6cm anteriorly and 1.6cm superiorly (Y, -1.6 and Z, 1.6). These hot spots were near the plane of Point A (X, 2.0 or -2.0; Y, 0; and Z, 2.0). The mean location of rectal hot spot was 1.6cm posteriorly and 1.9cm inferiorly (Y, 1.6 and Z, -1.9). D hot spot was affected by uterine wall thickness, uterine tandem position, fibroids, bladder fullness, bowel gas, and vaginal packing. Conclusions: Because of the location of the D hot spots, larger tumors present a challenge for adequate tumor coverage with a conventional brachytherapy applicator without an interstitial implant. Additionally, anatomic factors were identified which affect the D hot spot in OARs. © 2014 American Brachytherapy Society. 2 cc 2 cc 2 cc 2 cc 2 cc 2 cc 2 cc 2 cc 2 cc
  • Published In

  • Brachytherapy  Journal
  • Digital Object Identifier (doi)

    Author List

  • Kim RY; Dragovic AF; Whitley AC; Shen S
  • Start Page

  • 203
  • End Page

  • 209
  • Volume

  • 13
  • Issue

  • 2